Table 2. Real-time qPCR Primer.

Primer	Sequence (5′ to 3′)	Primer (bp)	Amplicon (bp)	Annealing temperature (°C)
PD-L1_2* s	AGACCACCACCACCAATTCC	20	173	60
PD-L1_2* /as	TGGAGGATGTGCCAGAGGTA	20	–	–
PD-L1_4** /s	AGCTATGGTGGTGCCGACTA	20	152	60
PD-L1_4** /as	CAGATGACTTCGGCCTTGGG	20	–	–
GAPDH in /s	GACCCCTTCATTGACCTCAACTA	23	102	60
GAPDH in /as	GAATTTGCCATGGGTGGAAT	20	–	–

^*amplification of transcript variant 1 and 2 simultaneously; amplicon named PD-L1_2

^**amplification of transcript variant 1 and 4 simultaneously; amplicon named PD-L1_4

The selected primers for RT-qPCR mRNA expression analyses of PD-L1_4 (including PD-L1 splicing variants 1 and 4) and PD-L1_2 (including PD-L1 splicing variants 1 and 2).